
      MODULE turb

      CHARACTER(len=64) :: TURBULENCE_MODEL

! If .TRUE. solve K_Epsilon turbulence eq.
      LOGICAL :: K_Epsilon

! Characteristic length for turbulence
      DOUBLE PRECISION, DIMENSION(:), ALLOCATABLE ::  L_scale

! Constant in turbulent viscosity
      DOUBLE PRECISION, PARAMETER :: Turb_C_MU = 0.09D0
! von Karman constant
      DOUBLE PRECISION, PARAMETER :: Turb_Kappa = 0.42d0

! Source term for K & Epsilon eq is linearized as
!    Source = K_Turb_G_c - K_Turb_G_p * K_Turb_G
      DOUBLE PRECISION, DIMENSION(:), ALLOCATABLE ::  K_Turb_G_c
      DOUBLE PRECISION, DIMENSION(:), ALLOCATABLE ::  K_Turb_G_p
      DOUBLE PRECISION, DIMENSION(:), ALLOCATABLE ::  E_Turb_G_c
      DOUBLE PRECISION, DIMENSION(:), ALLOCATABLE ::  E_Turb_G_p

! Diffusion coefficient for K & Epsilon
      DOUBLE PRECISION, DIMENSION(:), ALLOCATABLE ::  Dif_K_Turb_G
      DOUBLE PRECISION, DIMENSION(:), ALLOCATABLE ::  Dif_E_Turb_G

! Cross-corelation K_12 and time-scales in Simonin and Ahmadi
! models
      DOUBLE PRECISION, DIMENSION(:), ALLOCATABLE ::  K_12
      DOUBLE PRECISION, DIMENSION(:), ALLOCATABLE ::  Tau_12
      DOUBLE PRECISION, DIMENSION(:), ALLOCATABLE ::  Tau_1

      END MODULE turb
